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Korean Traditional Archery → Posts by ginni
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I have seen polish guy shooting with „turkished” korean bows. They changed the shape of the handle and shortened dramatically the string. I didnt shot their bows, but for me, used with the slender silhuette of the hwarang, the turkished version looked fat and odd.
I tried myself only with small changes in braceheight, it depend from a bow to another. Some bows had a cleaner pass, some worked better with shorter braceheight. However, I didnt tried braceheight longer than 6”.
A friend just bought a new Kaya bow, is 55 pounds. The upper limb has a twist, is not to the right but to the left side and few times the string came off when shooting. How can I fix it?
Hi Vali, and welcome! 
I doubt it can be drawn to 35”. According to the graph it should be over 120 lbs.
EM, as you can see, the 22lbs bow have over 43 lbs at 35". Is not very efficient by comparison with the more stronger bows.
Any longer version of YMG or SMG can be drawn safely @35" if is not strong, but will stack. Storm have a regular length SMG marked 49@28 (mauve in the second graph) and he shot a long time with 89-90 cm length arrows.
For YMG bows you can contact Bluelake. The site is here http://www.goongdo.com/product/bow.php
Kanuck, above is the bhutanese bow, which is whitout doubt a high performance longbow (not so long tough).
The energy stored is lower than hwarang:
SMG semihorn @28 has 68,18 lbs and 99,23 J energy.
SMG short 70 lbs@28 has 63,47lbs and 90,53 J energy.
YMG short 65lbs@ 28 has 61,16 lbs and 84,98J energy.
Bhutanese bow @28 65,24 lbs and 87,52J energy.
That because no longbow have a straight line curve of D/W graph.
And if you want a long bow to draw to 33", it should be very long and heavy, not so efficient.
However, I put the bhutanese in the chrono and got this:
Easton PowerFlight 353 grains @28:
Shooting with fingers, target style max.198 fps.
With snap technique I got max. 219 fps.
If we compare this with YMG who got 236 - target technique, same arrows, we can see the difference in efficiency. And YMG has less energy stored than buthanese bow at 28" draw.
I didnt tried with heavier arrows, Ill do that asap.
Peter, the 75lbs semihorn cannot be drawn to 35" safely. I must say the semihorn bow has a very big failure rate. As I know, here we got 10 bows and 6 has broken. Is a very pleasant bow to shot, but very unpleasant to break 
i have a long draw and I encouraged everybody to draw long, maybe this can be a problem. But the last who broke wasnt drawn longer than 31". Horn does not mix well with synthetic materials.
Draw-length is measured from belly to string, this should be from notch of arrow to base of the tip, for a longer point, with power flight is 1,5 cm from base ot the tip.
I have only some incomplete speed measurements, I have to do this more carefully.
If you want to know, for YMG marked 65@28, I got this (max speed, not average):
Easton Powerflight, 353 grains
draw length draw weight grains/lbs speed KE stored energy eficiency
28” 61,16 lbs 5,78 236 fps 59,28J 84,08J 70,50%
31” 69,68 lbs 5,05 265 fps 74,75J 107,27J 69,68%
I made this shooting with thumbring and I observed higher speeds with snap release, up to 15 fps, this is something I must to verify.
Peter, you are right, the 75,5 long SMG is semihorn, I forgot to mention.
Graph is based on empirical data (thick lines) and mathematical equations (thin lines) .
red: SMG long, marked 75,5 lbs @28
data:
draw 28” : force = 68,16 lbs, stored energy 99,23 joules
draw 29,5” : force = 74,92 lbs, stored energy 111,49 joules
draw 33” : force = 98,48 lbs, stored energy 145,69 joules
green: SMG standard, marked 70 lbs @28”
data:
draw 28” : force = 63,47 lbs, stored energy 90,53 joules
draw 29,5” : force = 70,31 lbs, stored energy 102,01 joules
drawe 33” : forta = 98,48 lbs, stored energy 134,69 joules
yellow: YMG standard, marked 65 lbs @ 28”
data:
draw 28” : force = 60,55 lbs, stored energy 84,08 joules
draw 29” : force = 64,86 lbs, stored energy 91,26 joules
draw 33” : force = 89,96 lbs, stored energy 126,08 joules
brown: SMG long, marked 50 lbs @28”
data:
draw 28” : force = 47,05 lbs, stored energy 69,46 joules
draw 29” : force = 50,02 lbs, stored energy 75,04 joules
draw 33” : force = 72,97 lbs, stored energy 102,46 joules
mauve: SMG standard, marked 49 lbs @28”
data:
draw 28” : force = 46,67 lbs, stored energy 63,67 joules
draw 29” : force = 50,47 lbs, stored energy 69,24 joules
draw 33” : force = 73,22 lbs, stored energy 97,00 joules
blue: SMG standard, marked 22 lbs @28”
data:
draw 28” : force = 20,08 lbs, stored energy 29,69 joules
draw 29,5” : force = 22,41 lbs, stored energy 33,45 joules
draw 33” : force = 31,92 lbs, stored energy 44,32 joules
draw 35” : force = 42,64 lbs, stored energy 52,85 joules
Speeds will come soon.
Kanuck, when I made my arrows I made an agreement, they don't interfere with my bow when I release the string, I let them free to go where they want 
)
I have one identical, I got if from Korea for a friend, but I didnt met him yet to give the bow. I can made some tests with it.
JBL, your bow is a YMG (that in the picture).
I cannot tell the differences between the four types presented on the bowyers site.
Two years ago I have seen few bows with some yellow/translucent belly, but I didn't liked the feeling, those bows were stacking badly, I think it was the time when the bowyer made some design tests.
Also I drew a very reflexed bow which I liked very much, but was only light draw weight.
However, after few mails, the bowyer convinced me he ca make the bow I want and he made a 74lbs@28”, long version, he called the bow „masterpiece”.
It was not a real masterpiece. Far away from the korean smoothness, the 70 lbs SMG was faster. And the biggest issue was with one limb, the lower limb started to lose the power and the bow became very unbalanced (no cracks and no apparent damage).
Mr. Park was very kind, he told is sorry about the issue and for about a year we was searching for a way to fix or replace the bow.
I met him in Korea this year and he changed the bow with a 65 regular one, medium length, which is an excellent bow. I bought another one, so much I liked.
In test is almost same range with 70 SMG, few meters short at flight shooting, I like this bow very much and is not that expensive „masterpiece”.
So, I think nobody can tell the differences between new and old hwarangs made by mr. Park from YMG. The bowyer knows, but I doubt he will tell you. He will say only that the new design is better!
Nice shot in the picture! I did many but I never split the arrow full length, do you wrap the nocks?
As I know, mr. Park from SMG works to open a factory in China. I believe is a high probability to be some quality issues when it will start production in China, beginning is not easy. His employers must to learn properly how to make a bow.
I glued only one pieces of skin, the cut is in the front (backing of the bow) of the handle.
If you sand the skin a little it will become almost abrasive, the handle will never slip.
Almost every year I made changes in my technique and in the shape of the handle. I started with classical korean pistol like handle and slowly going to the more middle-asian style.
SMG, 75 lbs semihorn. Ray skin. Excelent grip.
YMG, 65 lbs. Rubber ray skin imitation.
SMG 22#, soft leather.
Warbow, FMJ comes only in 32,5 inches, but I can obtain few mm from the nock and also the point is pretty long. So I think I draw 32,5 from notch to belly.
However, I did this in summer, when it was hot outside and hwarang loses power when is hot.
Also I have a semihorn bow from SMG which I think is the best, is 75lbs@28. Sunday I got with this bow 328 meters, by comparison with the 70 lbs which got only 301 meters.
I was surprised by a 65 lbs YMG bow, short, it shots 298 meters, very close to the more heavy 70 SMG.
I am waiting for the chrono to make speed test in cold.
Now I seen I made a mistake in my last post, with bamboo I got 218-220, not 318-320 fps, sorry!
I will put new numbers soon.
I found this korean way uncomfortable when I shot in low position, at close range. I am feeling better by drawing directly to the target and the time for aiming is shorter. When I shoot at distance, like 145 meters, korean way works fine.
I put my 70 lbs SMG into a chrono.
With Easton FMJ dangerous game, 32,5 length, 52,5 grams (818 grains), I got constantly 205 fps. With lighter arrows, 47-48 grams bamboo, I got 318-320 fps. I think this is 99,3 joules of kinetic energy.
Me either.
This bow is made in China. A friend had one which was very tuff, he shot with 5 to 10 grams short arrows and tonga very long time, the bow broke after one year. But I have seen also some delamination. The worst was that in the delaminated bow (new one) it was no resin between strips.
With this bow is lotery, is are lucky, you can get a good one.
Is very fast, but also unstable.
I have the chance to try the bows made by Yeung Mo Gung and Song Mu Gung, the last owning the factory who make the semihorn and bamboo belied bows.
I would like try to be short:
1. YMG bows feel to not staking at all, the best looking shape at full draw, very fast and extremly resistant at bad treatment.
If you want to put the bow on the limit, try this type. Little vibration in the hand.
2. SMG bows
- regular laminated bow is smoother than YMG, but it stacks earlier than YMG. Is very fast, not noticeable diferences between YMG and this bow. Very fine, long life but not very resistant at bad treatment, the first dry shot can destroy this bow.
- semihorn bow is the best shooting bow you can get, very tolerant, very very fast, very smooth, but severely stack at the draw limit. Not very long life and it required specialy care, like using a hot box. I like this bow the most, I had my best shots with this bow. The best sensation in the hand, after shooting this bow for a while, you will feel every other bow like having hand shock.
- bamboo belied bow, excelent look, is a beauty, is very smooth, but is slow. Little vibration also, comparable with YMG bow. Anyway, this bow, even is not the best shooter, is the best looking one. I dont know about the life of this bow, I tested them only for few days.
YMG use maple core, also maple in the fadeouts.
SMG made fadeouts from some synthetic material like impregnated fabric, and use bamboo for core.
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Korean Traditional Archery → Posts by ginni
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